Early elevator systems typically had indicators, at least on the lobby floor, of the floor position of the individual elevator. Later, elevator floor position in larger systems was typically provided only on a supervisory panel, where all the positions of all elevators were displayed side-by-side. Passengers were informed by "next car up" lights over the individual elevators of a group.
In the larger elevator systems where there may be three or more elevators serving a particular lobby landing, there is typically no warning that an elevator is about to arrive, and passengers must remain alert to the illumination of a floor lantern associated with a given elevator, and possibly the sounding of a relatively faint chime. In fact, it is common for passengers to press the hall call button and watch for it to be turned off as a clear idea that some elevator is coming, and thus they should look for a particular lantern to be lit.
Single elevator systems, typically hydraulic elevators, serving only a few floors, still typically provide an indication of the current elevator floor position. The purpose of this is more to advise potential passengers whether it's worth waiting for the elevator, or whether the passengers should alternatively use the stairs. In the smaller elevator systems, floor indicators, typically one light per floor over the elevator door or a mechanical indicator rotated in response to a cable connected with the position of the elevator car, can amount to a considerable portion of the expense for such a system. In order to make single elevator systems less expensive, the alternative has heretofore been to provide no indication of floor position, whatsoever.